Method of making high strength vinegar



Feb- 25, 1946. F. c. SILBERNAGEI.

METHOD OF MAKING HIGH STRENGTH VINEGAR resented Fet. 2e, 1946 UNITED STA-'resi VPnfrrs'Ni* l ME'rnon'r' Maxnvo man s'rnancrn,

vmnoaa 1 i Freuen-lek c. snbermrel. Manitowoe, wie., are

signor to A. M. Richter Sons Co.. Manitowoc, 'Y Wis., a corporation of Wisconsin aannemen January 12,1944, sei-1eme. vmima f' s clam (ci. ca -1m This invention *relates to thev manufacture of vinegar. As is well--known,.vlnegar is made 'by oxidizing an alcoholic mash with vinegar bacteria.

During the fermentation, the vinegar bacteria feeding on the alcohol content of the batch produces acetic acid. With past methods ofmaking vinegar, it has beenimposslble to produce natural vinegar -with a higher percentage of acetic acid than twelve (12) to twelve and one-half per cent U21/2% as twelve and one-half per cent (121/2 acetic acid is the extreme limit of acidity which vinegar bacteria can withstand.`

Vinegar with a higher acetic acid content is. of (course, very desirable. Aside from the saving.

in 4freight resulting` from` the use of higher strength vinegar, there is the more important advantage 'ot vmateriallyv reducing waste in the processing of pickled foods.

In the preparationA or processing of pickled foods, -the vegetable or fruit Juices dilute the vinegar-sugar brine below the point of safe concentration of acid. It thus becomes necessary for the manufacturer toincrease the acidity ofl the brine by adding fresh vinegar.

Obviously, the stronger the vinegar that is used,

` the less waste material'composed of dilute vine gar and other valuable constituents, such as sugar and spices. need be discarded. v

To illustrate, the average pickle packing plant operating on vinegar of 12% acetic acid content,

invention to produce vinegar .having an acetic. V`

acid content higher than 12%%, which involves .no subsequent process, but accomplishes its ob' -jective in the actual production of the vinegar.

Still another object or this invention is to pro- -vide a new and improved method vof making 4vinegar which although resulting in a product containing` a considerably higher percentage of acetic acid, nevertheless can be "practiced with sutfstantially the same equipment now used in' the manufacture oi' ordinary vinegar.

With the above and other objects in view; which will appear as thedes'cription proceeds. this' invention resides in the-,novel product and process of producing it substantially as herein-r after described, and .more particularly delined by the appended claims, it being understoodthat such changes in the precise embodiment of the herein' disclosed invention `may be made as come within the scope of the claims. In a broad general way `this invention consists in neutralizing the acetic acid produced bythe fermentation of the mash to produce an acetate unharmful to vinegar bacteria, followed by the after several months of opera-tion will have an appreciable amount of liquor on hand containing insuiilcient acetic acid and sugar and spices.

In an eiIort to conserve these essential ingredients, some food processors have used commercial acetic acid not produced by the fermentation process. The useofcommercial acetic acid, however. is not in the best interests of pure food. Hence, it is the general purpose of this invention to produce vinegar containing a higher-per-4 centage of acetic acid. In a broad sense, this has been accomplished in the past, but not in the actual production of the vinegar but rather asan adjunct thereto.

This past method consisted generally in'the production of vinegar in the ordinary manner followed by freezing out part of the water con- -tent to thereby increase the concentration of acetic acid. While the freezing method succeeds in' supplying pure vinegar of higher than-12% concentration, it involves anexpensive process, H

and, as stated, is not the result of the actual production of the vinegar itself, but rather tha of a subsequent process. z l

It is, therefore. ranother object et the present 65. o! the' generator whichcontains the ailing imaddition of alcohol to restore the substrate upon which the bacteria acts so that thebacterial action can be repeated `to produce more acetic acid.

Such neutralization of the produced acetic acid followed .by the addition o! alcohol :is repeated often enough to insure the desired concentration ilcient `alcohol is added to bring 'the entire contents to 13 proof alcohol so that with the addition of a sui'cient quantity of vinegar as starter, fermentation begins.

For a `specific illustration, the vinegar may be of a 5% acetic acid concentration. the

amountoi alcohol added need not raise theproofto 13, butv for purposes of illustratiom this value has beenI chosen as it represents substantially the maximum concentration of alcohol. which will not inhibit the bacterial action. l Y.

The mash is circulated over the upper reach f orales p i pregnated with vinegar bacteria so that oxidation of the alcohol content proceeds.

'I'his oxidation is allowed to continue until all but approximately 2 prodi of the alcohol is oxidized to acetic acid.

At this stage, as depictedy by the block 8 in the block diagram, the mash contained in the generator comprises approximately 2 proof alcohol and approximately 10% acetic acid.

A suiilcient quantity of slaked lime is then added (as indicated by the block 'i of the diagram) to the vinegar in the storage chamber of the generator to neutralize a portion of the acetic acid contained in the mash. The amount of acetic acid neutralized-is not critical and -or purposes of illustration, the diagram shows about a 50% neutralization.

As indicated by block 8, about half of the acetic acid, upon addition of the slaked lime, becomes bound in calcium acetate. A sulcient quantity of alcohol is then added (as indicated by block 9) to the mash to restore the proof to the original reading of 13. This is indicated by block lil.

v The resulting mash is continuously circulated over the iilling of the generator in the conventional mannerl until the newly added alcohol has been converted into acetic acid.

The addition of the slaked lime followed by restoration of the alcohol proof and oxidation of the alcohol is repeated until the free acetic acid plus the acetic acid obtainable from the calcium acetate lequals the amount desired, the process having been practiced to the pointof producing vinegar of 16% acetic acid concentration. No reason appears, however, why the process cannot be used to produce vinegar of much higher acetic acid concentration.

The entire mash is then discharged into an acidiiying tank (as indicated by block il) and sufficient sulphuric acid (block i2) is added to exactly combine with the .calcium acetate content.

' unal step ot removing possible traces or sulphate ion.

From the foregoingdescription, it will be read- .ily apparent to those skilled in the art, that this invention provides a method of producing so called high concentration vinegar which is wholly com- 'I'he reaction produces calcium sulphate (block I3) which is precipitated out and the free acetic acid (block I4) is then liberated from the calcium acetate. Traces of calcium sulphate ,in solution may be present in the acetic acid. It so all sulphate ion can be removed by treatment with a `calculated amountof barium hydroxide (block The resulting vinegar (block I8) is entirely l free of sulphate ion and has the desired concentration of acetic acid.

Most important, however, is the fact that all of the acetic acid is produced by the bacterial fermentation of the alcohol.

The calcium sulphate (block i3) or gypsum,

as it is commercially known, can be lter pressed,

dried and sold so that much of the original cost oi thesulphuric acid can be reclaimed.

This likewise applies to the small' amount of barium sulphate (block' I1) which may result from the nnal purification of the acetic acid where this step is deemed necessary.

' causing fermentation of the reiortiied solution,

patible with the pure food laws and one in which the entire process is one continuous sequence capable of being carried out with the equipment y used in the ordinary manufacture of vinegar.

What I claim as my invention is:

1. A process of producing vinegarcontaining a percentage oi acetic acid in excess of twelve per cent (12%) which comprises: oxidizing an alcoholic mash to vinegar by means of vinegar bacteria; sequentially neutralizing the acetic acid produced with a neutralizing reagent; refortiiying the mash with alcohol to permit further oxidation by'vinegar bacteria to acetic acid; and

'treating the solution with an acid to free the acetic acid from the acetate formed by the neutralization. A

2. The process of producing vinegar having a higher than twelve percent (12%) acetic acid concentration which comprises: oxidizing the alcohol content of a vinegar producing mash to form acetic acid; adding a suitable calcium salt tothe solution to neutralize its acid content and form calcium acetate; adding alcohol to the solution; causing fermentation of the refortied solution to oxidize the alcohol and produce more acetic acid; repeating the addition of the calciuml salt and alcohol until the free acetic acid plus the acetic acid obtainable from the calcium acetate supplies suicient acetic acid to give the vinegar the desired concentration; adding sulphuric acid to the solution to combine with the calcium acetate and free the acetic acid; and i'lltering out the calcium sulphate formed as the result of the addition ofthe su'lphuric acid.

3. The process of producing vinegar having a higher than twelve percent (12%) acetic acid' concentration which comprises: oxidizing the a1- cohol content of a vinegar producing mash to form acetic acid; adding slaked lime to the solution to neutralize its acid content and form calcium acetate; adding alcohol to the solution;

to oxidize the alcohol and produce more acetic ylil) l the desired concentration;

acid; repeating the addition of the slaked lime and alcohol until the free acetic acid plus the acetic acid obtainable from the calcium acetate supplies sufiicient acetic acid to give the vinegar adding sulphuric acid to the solution to combine with the calcium acetate and free the acetic acid; precipitating the calcium sulphate resulting from the addition of the Sulphuric acid; and removing any remaining traces of soluble sulphate from the solution by the addition ofv a suitable quantity of barium hydroxide.

4. 'The process of producing vinegar having a higher than twelve percent (12%) acetic acid concentration which comprises: oxidizing the alcohol content of a vinegar producing mash to form aceticvacid; adding. a metallic salt which will form lan insoluble sulphate to the solution to Aneutralize part of its acid content and form an acetate of the metallic salt used; adding alcohol and calcium oxide so deposited would b'e noxious.

Also, if cost were not a factor, the more expen- I sive barium salts, barium oxide, barium hydroxide,

to the solution: vcausing fermentation o2 the rey fortliied solution to oxidize the alcohol and produce more acetic-acid; repeating the addition oi the metallic salt and alcohol until the free acetic acid plus the 'acetic acid obtainable from the 'acetate supplies sunicient acetic acidi-,o give the A' 'from the vinegar the desired concentration: and treating the solution with im. acid to iree the acetic acid from the acetate.

5. The process oi' producing vinezar having a higher than twelve percent (12%) acetic acid concentration which comprises: oxidizing the alcohol content of a, vinegar producing mash to form acetic acid; adding a barium salt to the solution to neutralize part of its acid content and form anf'acetate of the Barium salt used: adding alcohol to the solution; causing fermentation of the reiortiiled solution `tooilidize the alcohol and producemore acetic acid; repeating the addition otthehbarium salt and alcohol until the free acetic acidplus the acetic acid obtainable from the acetate supplies suiiicient acetic acid to sive the vinegar the desired concentration; and 'tx'eatinii A` `anacidto irectheaceticactd tho solution with wenn producing vinegar having a 6. The process of higher than twelve percent (12%) acetic acid' concentration which comprises: oxidizing the alcohol content of a vinegar producing mash to form acetic acid; adding calcium carbonate to the solution to neutralize Part of its acid content and form a' calcium acetate; adding alcohol to the solution; causing fermentation of the refortified solution to oxidize the alcohol and prouncommon c. 4- 

